Utilizing surface modification in coating technology to enhance the efficiency of CL-20 desensitization

Abstract

To reduce the mechanical sensitivity of CL-20, this study is based on the surface modification of CL-20, and explores the effects of two preparation processes, the water solution-suspension method and the phase separation method, on the coating process of CL-20. Based on the structural characteristics of surfactants, a formulation was devised, using 2-cyanoethyltriethoxysilane (SCA2) as the surfactant and microcrystalline wax as the desensitizer. The samples underwent comprehensive characterization employing SEM, XPS, DSC, XRD, friction sensitivity testing, and impact sensitivity testing to evaluate both their structural composition and inherent properties. The results showed that the composite particles prepared using the phase separation method displayed a compact coating layer on CL-20 surfaces. Specifically, the composite particle CL-20@SCA2/Wax-P, which contained the surfactant, exhibited a thin and dense film on its surface. The proportion of -NO₂ groups on the surface of the composite particles experienced a reduction of 13.12% compared with CL-20. The crystal form of CL-20 remained unchanged in four composite particles. The decomposition peak temperatures and activation energy of all four composite particles were decreased, resulting in reduced thermal stability. The critical friction sensitivity load for composite particles produced via the aqueous suspension method is 252 N, whereas for those prepared using the phase separation method, it elevates to 360 N. The characteristic drop height (H₅₀) of composite particles prepared by the phase separation method increased significantly, 34 cm for CL-20/W-P composite particles and 55 cm for CL-20@SCA2/W-P composite particles, compared with the raw CL-20. These results suggest that the utilization of SCA2 effectively modified the surface of CL-20, and the composite particles prepared using the phase separation method demonstrated a considerable reduction in mechanical sensitivity.